Abstract

Extensionalism is, roughly, the view that perception occurs in episodes that are temporally extended (and thus capable of accomodating in their entirety phenomena taking a nonzero lapse of time to occur). This view is widely acknowledged to be incompatible with thin presentism, the second most popular position in temporal ontology. In this paper, I argue that extensionalism is also incompatible with several other positions in temporal ontology, namely those positing the existence of non-present times that host sentience—positions I collectively refer to as the sentient non-present view. Most notably, extensionalism proves to be incompatible with B-theoretical eternalism, which is the most popular position in temporal ontology.